1. Field of the Invention
The present invention relates to a scheme for interactive video manipulation and display in which a background image is displayed on a computer screen on which a position is interactively specified by a user using a pointing device such as mouse, touch screen, etc., and a partial image of a moving object that is set in correspondence to that specified position is synthetically displayed at that specified position so as to express a series of actions of the moving object on the background image.
2. Description of the Background Art
The conventionally known examples for carrying out some manipulations related to the video display on a computer includes that which displays a corresponding frame image by manipulating a time axis with respect to a video image. For example, in the QuickTime player of the Apple Computer Inc., as shown in FIG. 1, when a slider (a time axis cursor) corresponding to a time axis is manipulated to specify a specific time, a frame image corresponding to the specified time is displayed on a display window. In this example, there is no manipulation related to the image space so that it is an example for expressing the video solely on the time axis basis.
On the other hand, the QuickTimeVR player of the Apple Computer Inc. is an interface in which a panorama image of large aspect ratio is viewed through a window, which employs a mechanism by which a hidden portion located outside the window can be displayed according to a right or left movement of a mouse cursor (field of view moving cursor), as shown in FIG. 2. In this case, the window is virtually moved with respect to the background image according to an amount and a direction of relative displacement of a mouse. In this example, there is no time axis information and no manipulation on the displayed image itself, and only the field of view of the window is manipulated.
From a viewpoint of the interactive display of video, in particular, the conventional schemes such as those described above are mostly examples in which only a time axis is manipulated on solely time axis basis as in the example of FIG. 1, and even in the example of FIG. 2 which is not directed to the manipulation on time axis basis, the direction and the relative amount of displacement for the mouse cursor manipulation are used only for manipulating a field of view of the window and there is no manipulation of information that is directly related to a position on the actual background image.
Thus conventionally there has been no interface for interactively manipulating the display on basis of positions on the background image.
Now, the video playback speed can be changed to a prescribed playback speed as in the case of the fast forward playback mode in a general video playback device or to arbitrary playback speed in some devices, where the video is playbacked from a current position until a stop request is issued according to inputs from buttons, jog shuttle, slider, etc. At this point, most of the conventionally known devices only offer the video display.
In the prior art, the playback end point is not to be specified in advance, so that when a user carries out the fast playback, for example, it is necessary for the user to watch the displayed video image carefully in order to judge a proper playback end point and therefore there is a heavy load on the user. As a method for specifying the playback end point, it is possible to consider a method in which a time code or a frame number of the video image is to be entered, but this method lacks the intuitive feel, so that there is a need for a method in which an input can be made while visually checking the video image of the playback end point. In this regard, a method in which the video image is divided at equal intervals and top images of the divided intervals are arranged as static images is not desirable as it would require a separate region or monitor for displaying the playbacked video image.
Moreover, in the case of playbacking sounds, there is a problem that the sounds as a whole will become difficult to listen to as they will be pitched higher in the case of fast playback or lower in the case of slow playback.